Since the information for transforming functions in the genomes of oncogenic viruses is insufficient to account for the variety of changes sustained by transformed cells, amplification of that information may be necessary for facilitation and maintenance of neoplastic transformation. As a vital link between the environment external to the cell and the intracellular space, the plasm membrane is an appropriate site for amplification of transforming functions. In an analogous manner, membrane-events appear to trigger a variety of biological phenomena--e.g., lymphocyte blastogenesis, hormone actions, and oocyte fertilization. The following membrane-related functions are abnormal in transformed cells: adhesiveness to substrate, agglutinability by lectins, levels of cyclic AMP, and transport of sugars, amino acids and nucleic acid precursors. Although each of these represents separately generated events, physical and chemical measurements of the plasma membrane of normal and transformed cells indicate an as yet ill-defined, basic difference between the two, which might generate differences with respect to adhesiveness, agglutinability, transport, and cyclic AMP levels. This basic difference may be the nature of the lipid bilayer of the plasma membrane, which must affect the function of membrane proteins. We intend to measure these activities in plasma membrane vesicles from normal and transformed cells grown in vitro to establish whether transfromation defects in the membrane activities described do, in fact, reflect a plasma membrane lesion. The mobilities of at least two of the proteins responsible for two of those activities will be measured by fluorescence polarization spectroscopy and the boundary lipid will be extracted and identified. With the expectation that differences in function of plasma membrane vesicles from normal and transformed cells can be understood in terms of the mobilities of membrane proteins and their boundary lipid, the plasma membrane vesicles will be fused with "artificial" lipid or protein-lipid vesicles or liposomes to explore the molecular mechanisms by which plasma membrane functions are modified and regulated.